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How to boost your immune system for increased health
Many emergency service workers and their families enjoy the flexibility and variety that shift work can offer. However, shift work can bring with it a particular set of challenges relating to general wellbeing and increasing the risk of poor health outcomes, such as poor nutrition, lack of exercise, poor sleep quality, and lack of social connectedness to name a few.
As emergency service workers you come in contact with many potentially unwell people in many challenging situations. Given that you are unable to control your environment it makes sense to try and maintain a routine of healthy eating and exercise (particularly if doing shift work) to give your body the best chance of avoiding infection and remaining well.
Read: Shift Work: Maintaining the balance and A comprehensive guide on meals and shopping lists around shift work.
Green vegetables, exercise and meditation are often touted as immune system boosters; but as far as scientists such as Professor Marc Pellegrini, Division Head, Infectious Diseases and Immune Defence at The Walter and Eliza Hall Institute of Medical Research are concerned, vaccines are the only thing that will boost your immune system to prevent infection. Professor Pellegrini has stated that "Vaccines boost the capacity of the immune system to a fight an infection, because you're exposing it to a pathogen that it will recognise next time".
But first, let's unpack how your immune system works and why some people have better immune systems than others.
What happens when your immune system meets a virus?
Your immune system is made up of different types of cells and molecules, such as antibodies. The first line of defence is what's known as our innate immune system. Professor Pellegrini advises that every cell in your body is primed to make interferons — antiviral molecules — when they detect an intruder. These cells will start to make their own inherent antiviral molecules that will try and stop, for example, viruses from replicating. This innate response, which kicks in immediately, produces substances called cytokines, which cause fever and inflammation of the tissues as the cells start to die.
There are also white blood cells, known as natural killer cells, which detect infected cells and kill them. The second line of defence occurs in a spectrum of other white blood cells such as monocytes, macrophages and neutrophils that survey the environment and try and recognise infection, and release immune hormones to try and prepare other cells for the likely scenario that they might get infected. The third line of defence is the adaptive system, which takes several days to kick in. These are white blood cells such as T-cells that try to kill infected cells, and B-cells that produce antibodies that either neutralise the bug or coat them with a substance so they can be recognised by the T-cells. The problem with the new SARS-Cov-2 virus is that we have no antibodies or adaptive immune system. If the immune system can't stop the virus replicating, it goes into overdrive and ramps up inflammation, especially in the lungs. This is what causes viral pneumonia.
"This is where it's critical for our body to be nimble. And the nimble part of the immune system is the innate system" says Dr Pellegrini.
Do some of us have weaker immune systems?
The immune systems of the very old and the very young are weaker than most other people. As you age, some of the cells also age and become a little less nimble in their capacity to respond to the infections. People who are immunocompromised are also more vulnerable to infection. This includes people who have a disease or are taking a drug that suppresses their immune system such as those with autoimmune conditions such as rheumatoid arthritis, cancer who are undergoing chemotherapy and people who have had organ transplants.
What can put your immune system under stress?
If you are already fighting an infection, conditions such as heart disease, lung disease and diabetes may also put more load on your body's ability to cope and function. For example, if the heart doesn't have capacity to deliver oxygen to the body it has to beat harder, which in turn can cause a heart attack. Or if part of the lung is damaged there is less ability to get oxygen into the blood.
Having a concurrent infection, such as the flu, can also make it harder for your immune system to cope, which is why doctors are recommending you get a flu shot to help protect yourself during the Tasmania flu season.
Stress may also affect your immune system. If you're under tremendous psychological stress then your adrenaline and cortisol levels will be high and these too could impact immunity.
How Does Food Affect Your Immune System?
It’s difficult to overstate how important nutrition is in promoting a healthy immune system. You need a diverse group of nutrients to create a strong barrier against pathogens that would otherwise make you ill. Making healthy food choices is like recruiting a microscopic army of nutrients which are all trained to help your body fight off germs.
So, what foods should you be eating to get the nutrients you need to stay healthy?
Are some foods better for your immune system?
Anything that makes your heart healthy, your lungs healthy, and kidneys healthy, will make your immune system healthy. There is no diet, other than avoiding highly processed foods loaded with sugar. Keeping your immune system healthy is about general nutrition.
Professor Clare Collins, a dietitian at the University of Newcastle agrees there is no one food that can magically supercharge your immune system. Nutrients from a range of healthy foods are needed in the biochemical pathways that are triggered as your body fights an infection. The idea is to eat a range of foods that contain vitamins A, B, C, D and E and the minerals iron, zinc and selenium.
Good sources of vitamins
- Vitamin A: oily fish, egg yolks, cheese, tofu, nuts, seeds, whole grains and legumes
- Vitamin B6 (riboflavin): cereals, legumes, green leafy vegetables, fruit, nuts, fish, chicken and meat
- Vitamin B9 (folate): green leafy vegetables, legumes, nuts and seeds and commercial bread-making flour
- B12: animal products, including eggs, meat and dairy, and also in fortified soy milk (check the nutrition information panel)
- Vitamin C: oranges, lemons, limes, berries, kiwifruit, broccoli, tomatoes and capsicum
- Vitamin D: mainly sunlight, but is also found in some foods such as eggs, fish, while some milks and margarine brands may be fortified with it.
- Vitamin E: nuts, green leafy vegetables and vegetables oils.
- Iron: meat, chicken and fish. Vegetarian sources include legumes, whole grains and iron-fortified breakfast cereals
- Zinc: oysters and other seafood, meat, chicken, dried beans and nuts
- Selenium: nuts, especially Brazil nuts and meat, cereals and mushrooms.
These micronutrients play important roles in both the innate and adaptive immune systems in the production of different types of cells.
In addition to this, Vitamin A and Zinc helps to maintain the integrity of the skin and lining of vital organs and the respiratory system (which are part of the innate immune system). Vitamin B12 and Iron are also essential for the production of haemoglobin which carries oxygen in the blood. Vitamin C, E and Selenium help to control inflammation by mopping up the impact of oxidative stress produced by free radicals that pierce cell walls causing the contents to leak.
What about taking extra vitamins?
Taking additional vitamins is not necessary unless you have been diagnosed by your doctor with a specific nutrient deficiency such as vitamin D, or you have specific dietary needs because you are pregnant or have been diagnosed with a condition that can affect the absorption of nutrients such as cystic fibrosis or gut disorders. There is no conclusive evidence that Vitamin C supplements can delay the onset of an infection or treat respiratory infections.
How does exercising affect my immune system?
Many studies show that long-term exercise is beneficial not only for the immune system but also keeping your heart and lungs healthy.
There are many ways to continue an exercise program even when you are physically distancing. But take it slowly if you're not accustomed to exercising. Professor Pellegrini advises that you don't suddenly try to run a marathon thinking that you will suddenly become fit and resilient. You'll be more susceptible to infection because you’ve diverted a huge amount of energy into building muscle and fitness — energy that is useful to the immune system.
Want more resources?
Through MyPulse you can access a range of resources and services to assist with nutrition, exercise, sleep and self-care and many other topics to help you manage your physical health and mental wellbeing.
Your Defence System helps you plan for the three pillars of good health: Sleep, Physical Activity and Nutrition.
Eat for Health have some great healthy meal and snack ideas to help you look after yourself and your family during these challenging times.
If you haven't completed the MyPulse Mental Health or Physical Health & Wellbeing Screens already, they are a great place to check-in and see how you are tracking in a range of health and wellbeing measures which can have an impact on immune system. Each screen is a series of questions about behaviours, actions and feelings - they are completely confidential, take between 5-10 minutes each to complete and you can even do them on your mobile device – anywhere, anytime.
If you present with moderate or high-risk factors you may be offered follow-up confidential coaching support by our qualified MyPulse Coaches to help maintain and improve your wellbeing.
Sources:
Professor Marc Pellegrini, Division Head, Infectious Diseases and Immune Defence at The Walter and Eliza Hall Institute of Medical Research
Professor Clare Collins, Dietitian, University of Newcastle
